from django.shortcuts import get_object_or_404, render
from django.http import Http404, HttpResponse, HttpResponseRedirect
from django.urls import reverse
from django.views import generic


# Create your views here.
from .models import Question, Choice
from django.template import loader

class IndexView(generic.ListView):
	template_name = 'polls/index.html'
	context_object_name = 'latest_question_list'
	def get_queryset(self):
		return Question.objects.order_by('-pub_date')

class DetailView(generic.DetailView):
	model = Question
	template_name = 'polls/detail.html'

class ResultsView(generic.DetailView):
	model = Question
	template_name = 'polls/results.html'


def vote(request, question_id):
	question = get_object_or_404(Question, pk=question_id)
	try:
		selected_choice = question.choice_set.get(pk=request.POST['choice'])
	except (KeyError, Choice.DoesNotExist):
		return render(request, 'polls/detail.html', {
			'question': question,
			'error_message': "你没选",
			})
	else:
		selected_choice.votes += 1
		selected_choice.save()
        # Always return an HttpResponseRedirect after successfully dealing
        # with POST data. This prevents data from being posted twice if a
        # user hits the Back button.
		return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))